ABSTRACT
Additive manufacturing (AM) techniques have provided many opportunities for the rational design of porous metallic biomaterials with complex and precisely controlled topologies that give rise to unprecedented combinations of mechanical, physical, and biological properties. These favorable properties can be enhanced by surface biofunctionalization to enable full tissue regeneration and minimize the risk of implant-associated infections (IAIs). There is, however, an increasing need to investigate the immune responses triggered by surface biofunctionalized AM porous metals. Here, we studied the immunomodulatory effects of AM porous titanium (Ti-6Al-4V) printed using selective laser melting, and of two additional groups consisting of AM implants surface biofunctionalized using plasma electrolytic oxidation (PEO) with/without silver nanoparticles. The responses of human primary macrophages and human mesenchymal stromal cells (hMSCs) were studied in terms of cell viability, cell morphology and biomarkers of macrophage polarization. Non-treated AM porous titanium triggered a strong pro-inflammatory response in macrophages, albeit combined with signs of anti-inflammatory effects. The PEO treatment of AM porous titanium implants showed a higher potential to induce polarization towards a pro-repair macrophage phenotype. We detected no cytotoxicity against hMSCs in any of the groups. However, the incorporation of silver nanoparticles resulted in strong cytotoxicity against attached macrophages. The results of this study indicate the potential immunomodulatory effects of the AM porous titanium enhanced with PEO treatment, and point towards caution and further research when using silver nanoparticles for preventing IAIs.
Subject(s)
Biocompatible Materials/chemistry , Porosity , Printing, Three-Dimensional , Prostheses and Implants , Titanium/chemistry , Alloys/chemistry , Biomarkers/metabolism , Bone Regeneration , Cell Survival , Cells, Cultured , Humans , Immunomodulation/drug effects , Inflammation , Ions , Lasers , Leukocytes, Mononuclear/cytology , Macrophages/metabolism , Materials Testing , Mesenchymal Stem Cells/cytology , Metal Nanoparticles/chemistry , Monocytes/cytology , Nanoparticles/chemistry , Phenotype , Polyethylene Glycols/chemistry , Silver/chemistry , Stress, Mechanical , Surface PropertiesABSTRACT
The use of antibiotics in the Children Hospital of Florence has been studied considering the whole hospital for 1979 and only one department for 1980-81. 7832 clinical records of children admitted to the Hospital have been analyzed in order to get more informations about the quality of antibiotic treatment and to understand the causes of use and misuse of this kind of drugs in pediatric practice.
